Transfer of Frozen Embryos Doesn’t Raise Live-Birth Rate

Last Updated: January 10, 2018.
Transfer of frozen embryos does not increase the live-birth rate for ovulatory women with infertility or for women without polycystic ovary syndrome who are undergoing in vitro fertilization, according to two studies published in the Jan. 10 issue of the New England Journal of Medicine.

No increase in live-birth rate with frozen embryos for ovulatory women with infertility, those without PCOS

WEDNESDAY, Jan. 10, 2018 (HealthDay News) -- Transfer of frozen embryos does not increase the live-birth rate for ovulatory women with infertility or for women without polycystic ovary syndrome who are undergoing in vitro fertilization (IVF), according to two studies published online Jan. 10 in the New England Journal of Medicine.

Yuhua Shi, M.D., Ph.D., from Shandong Provincial Hospital-Shandong University in Jinan, China, and colleagues randomized 2,157 ovulatory women with infertility who were undergoing their first IVF cycle to undergo fresh-embryo transfer or embryo cryopreservation followed by frozen-embryo transfer. The researchers observed no significant difference between the groups in the live-birth rate (48.7 versus 50.2 percent for the frozen-embryo and fresh-embryo groups, respectively; relative risk, 0.97 [95 percent confidence interval, 0.89 to 1.06; P = 0.5]).

Lan N. Vuong, M.D., Ph.D., from the University of Medicine and Pharmacy at Ho Chi Minh City in Vietnam, and colleagues randomized 782 infertile women without polycystic ovary syndrome who were undergoing a first or second IVF cycle to receive a frozen or fresh embryo. The researchers found that ongoing pregnancy occurred in 36.3 percent of the frozen-embryo group and in 34.5 percent of the fresh-embryo group (risk ratio, 1.05 [95 percent confidence interval, 0.87 to 1.27; P = 0.65]). After the first transfer, the rates of live birth were 33.8 and 31.5 percent, respectively (risk ratio, 1.07; 95 percent confidence interval, 0.88 to 1.31).

"The transfer of frozen embryos did not result in significantly higher rates of ongoing pregnancy or live birth than the transfer of fresh embryos," Vuong and colleagues write.

Several authors from both studies disclosed financial ties to the pharmaceutical industry.